This invention relates to concrete assembly systems, and specifically to a concrete anchoring, lifting, erection, and construction apparatus and method that provide removability, reusability and ease of use. The present invention lends itself to various applications, including, for example, buildings, freeways, and other heavy construction which involve erection and assembly of large panels or columns of material such as pre-cast or cast-in-place concrete.
Heavy panels or other pieces of construction material are conventionally transported, raised and positioned for assembly with the use of anchors and lift systems such as those depicted in FIGS. 1A and 1B, and as disclosed in U.S. Pat. No. 4,615,554 to Schilla, et al. Referring to FIG. 1A , for example, such prior art systems may include a permanently cast plate 1, mounted perpendicularly to a permanently cast anchor 2, which is connected a hook mechanism 3, and secured by an anchoring bolt 4. Cranes or similar devices are attached to the hook 3, and the panel is then transported, raised and positioned as needed.
Similarly, referring to FIG. 1B, such systems may include a surface lifting plate 5, connected to a hook mechanism 6 and mounted onto a permanently cast anchor 7, secured by an anchoring bolt 8. Such systems may further incorporate a permanently cast sleeve 9, which is secured to and creates a cavity about a permanently cast anchor 7, in order to permit the subsequent injection of grout or a similar adhesive compound (for affixing the panel or column in a permanent location), as generally described below in connection with FIGS. 1C and 1D.
In order to accomplish lifting and positioning of one or more panels in these prior art systems, the user typically casts several plates and anchors into each such panel, attaches hooks (although some prior art applications include hook-anchor combinations) and bolts (either before or after casting of the panel), and further takes the time to detach the hooks (if possible) and bolts after positioning, but before final assembly. The assembly and disassembly of such systems are cumbersome and time consuming (thereby increasing the risk to nearby workers and equipment), have very tight tolerances, and require the user to leave at least the anchor and plates in or on the panels even after final assembly.
Other prior art panel connection systems involve similar limitations. Examples of such other systems include permanently cast sleeves, such as depicted in FIGS. 1C and 1D, and plate connections, such as depicted in FIG. 2.
In a permanently cast sleeve system such as depicted in FIGS. 1C and 1D, a grout sleeve 105 typically is used to create void space in the column or panel, into which a connecting mechanism such as conventional rebar 106 may be inserted. Tubes 107 can then be used to inject grout or a similar adhesive into the void space surrounding rebar 106. As shown in FIG. 1D, several grout sleeves 105 may be cast into a column or panel along with pieces of conventional rebar 106, so that void space created by the grout sleeves 105 is capable of receiving the rebar 108 protruding from and cast into a separate column or panel 109. Such sleeves may also include threaded inner surfaces to permit threaded connection with anchor and hook lift assemblies similar to those discussed above, such as disclosed in U.S. Pat. No. 5,261,198 to McMillan. Even more complex insert assembly systems for creating void space in such materials are disclosed by U.S. Pat. No. 4,679,362 to Mess and U.S. Pat. No. 4,338,715 to Capers.
In a plate connection system such as shown in FIG. 2, rebar 250 is set into the panel or column, and an exposed metal plate 260 is then connected (typically via welding) to the rebar. When adjoining panels or columns are to be connected (including when a panel is to be anchored to a foundation or footing), the metal plate 260 is then welded to corresponding metal plate 270, as illustrated by the arrow in FIG. 2.
Like the anchor and plate lift systems discussed above, other previously known connection systems (including both sleeve and plate types) require the user to leave substantial single-use accessory materials permanently cast in the panel or column after final assembly, thus increasing construction costs due to inability to reuse some or all of those components of the system. Moreover, the components which remain in the panel or column arc typically made of metal, thus increasing the possibility of rust, and consequently, decay and possible failure of the connection. In addition, the substantial cost of single-use prior art equipment often results in an insufficient number of components being used in a given application, thereby further increasing the risk of such failure.
It is, therefore, an object of my invention to provide an apparatus for use in the assembly of concrete material, characterized by a body having a first portion configured to be set into concrete during the casting of that concrete, and which can be removed from the concrete after the concrete has set, and thereby may be reused in a similar manner with other concrete. The body of the apparatus preferably includes a serrated exterior surface to increase the adhesion that may be achieved when joining parts together, and to enable the dispersion of lifting and load forces during transportation of the concrete, as described herein. Certain configurations of serrations can also facilitate removal of the apparatus from the concrete after casting. The serrated exterior may be preferably configured to interferingly engage with at least one reinforcing element formed in the concrete, in order to assist in lifting or other positioning of the concrete for assembly.
Another object of my invention is the provision of an apparatus of the aforementioned character, in which the aforementioned body is generally cylindrical and includes a second portion configured to facilitate rotation of the first portion of the body about its longitudinal axis to facilitate removal of the apparatus from the concrete. The apparatus may be further engageable with machinery capable of providing a continuous supply of relatively rapid setting concrete, thus providing substantial ease and economy of use over conventional prior art extrusion concrete apparatus and techniques.
A further object of my invention is the provision of an apparatus of the aforementioned character, in which the second portion of the body includes an engagement member with which other devices may be engaged to facilitate positioning of the concrete for assembly prior to removal of the apparatus from the concrete.
A still further object of my invention is the provision of an apparatus of the aforementioned character, in which the engagement member includes an aperture configured to permit access by those other devices.
Another object of my invention is the provision of an apparatus of the aforementioned character, in which the engagement member is separable from the body.
Yet another object of my invention is the provision of an apparatus of the aforementioned character, in which the first portion of the body is inflatable, and is removable from the concrete by deflating.
My invention thus provides numerous advantages over the single-use, non-removable devices of the prior art, including, by way of example and not limitation, elimination of welded plates or permanently cast sleeves which remain exposed when panels or columns are to be joined to one another, thereby also improving ease of installation and use, and consequently lowering the risk of rust or other deterioration of joints between concrete elements.
Another object of my invention is the provision of a method of use of an apparatus of the aforementioned character, including various combinations of the steps of providing concrete material, providing a form for casting the concrete material, positioning the apparatus in a selected position with respect to the form to facilitate the eventual removal and reuse of the apparatus, casting the concrete material in the form and around the apparatus, and removing the apparatus from the concrete material after casting. The removal step may further consist of rotatably removing the apparatus from the concrete material.
Yet another object of my invention is the provision of a method of the aforementioned character, including the steps of providing at least one reinforcing element, and positioning the reinforcing element in the concrete casting form between adjacent serrations on the exterior surface of the apparatus.
Still another object of my invention is the provision of a method of the aforementioned character, in which the apparatus is inflatable and the method includes the steps of inflating the apparatus prior to casting the concrete material, and deflating the apparatus to facilitate its removal from the concrete material.
A further object of my invention is the provision of a method of concrete construction, including various combinations of the steps of forming an element from concrete about a removable insert with an exposed gripping portion, gripping the gripping portion of the insert to transport the concrete element to a selected final position, removing the insert, and reusing the insert. Further steps may include positioning the concrete element so that the void created by removal of the insert is about a connecting element configured to connect the concrete element to another thing (for example and not by way of limitation, another concrete element), and pouring grout into the void and around the connecting element to provide a connection between the concrete element and the other thing.
Another object of my invention is the provision of a system for fastening discrete elements to each other, which systems includes two or more discrete elements, with one or more inserts formed in at least one of the elements. Preferably, the insert or inserts are removable from the element to form a void in the element, and at least one other of the discrete elements includes corresponding extension members insertable into the void or voids. Joining material may be injected into the void around the corresponding extension member to relatively permanent bond said discrete elements to each other. In certain applications, the elements in this system may be formed from concrete, and the extension member may be a metal rod.
Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawings, which are for the purpose of illustration only.